code: def setUpClass(cls):
      for attr in dir(cls):
          if attr.startswith("test"):
              fn = getattr(cls, attr)
              setattr(cls, attr, cls.join_or_run(fn))
  
file_path: CrypTen/test/multithread_test_case.py
imports: import queue
  import sys
  import threading
  import unittest
  from functools import wraps
  from threading import Thread
  import crypten
label_desc: Use image node_id 4 for calling the MultiThreadTestCase obj's underlying member method code with example usage: obj.setUpClass(cls) without return types